Influence of coalification on microstructure characteristics of coal surface

doi:10.16265/j.cnki.issn1003-3033.2020.01.019

Abstract

Abstract: In order to study influence of coalification on microstructure characteristics of coal, with coal at three different metamorphic grades selected as samples, their surface pores and shape distribution were studied by using SEM. Then, types and distribution of surface functional groups were explored by FTIR spectrometer. When R₀ of HP-SH coal sample increased from 0.70% to 2.88%, surface pores tended to be rough and more complicated with a porosity ranging between 65.29%-77.07%. Relative content of oxygen functional groups gradually increased with an relative ratio of -O- between 10.1% -19.25%, that of -OH between 7.16%-41.79% and -COOH between 52.01%-51.96%. Aromaticity and polymerization degree also gradually increased with aromaticity ranging between 1.09-1.63 and the other 0.29-1.58, and aromatic structure parameters of coal samples kept a linear relation with surface porosity. The results show that functional groups on micro-surface of coal samples will be similar as coalification degree becomes greater. The more complex functional group structure is, the more complicated that of micro-surface pore will be, thus providing an environment for micro-surface to reserve gas.

Key words: coalification, scanning electron microscopy (SEM), Fourier transform infrared (FTIR), surface porosity, surface functional group

CLC Number:

X915.5

LIU Huifang, SONG Dazhao, HE Xueqiu, TIAN Xianghui, LOU Quan, WANG Weixiang. Influence of coalification on microstructure characteristics of coal surface[J]. China Safety Science Journal, 2020, 30(1): 121-127.

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